This invention relates to an improved apparatus for determining Brinell hardness. More particularly, the invention relates to an improved apparatus for determining the Brinell hardness of railway vehicle wheels.
Brinell ratings are used extensively throughout industry as a measure of material hardness. One such use involves the testing of railway car and locomotive wheels. Because many separate wheels require testing, an efficient and reliable apparatus is desirable. In many instances the surface of the wheels needs to be polished in order to determine accurate hardness ratings. In the past, the various operations involved in Brinell testing of such wheels have resulted in excessive and time consuming movements of the wheel, for example, performing certain operations with the wheel in a horizontal position and other operations with the wheel in a vertical orientation. Clearly, an improved Brinell hardness apparatus for testing railway vehicle wheels would be advantageous.
An improved apparatus for determining the Brinell hardness of railway locomotive and car wheels has now been discovered. The present apparatus comprises a wheel receiving means which acts to receive and retain a railway vehicle wheel in a substantially vertical position during the testing operations.
In any event, the present apparatus further includes an elevator means, preferably powered by an air or hydraulic cylinder-piston assembly, which is positioned with respect to the receiving means so as to raise or lower the receiving means, preferably in a substantially vertical plane, as desired. Thus, when the receiving means is retaining a wheel in the substantially vertical position, the elevator raises or lowers this wheel, preferably straight up or down, as desired.
A polishing mechanism is included in the present apparatus. In order to obtain accurate and reliable Brinell hardness ratings, that portion of the wheel's surface which is to be tested should be thoroughly cleaned or polished so as to expose the base metal. Before the Brinell hardness determinations are made the polishing mechanism is located adjacent the travel path of the elevator in such a position as to polish at least a portion of the surface of the wheel being retained by the receiving means as the wheel is moved in a substantially vertical plane by the elevator.
In a preferred embodiment of the present invention, the polishing mechanism comprises a belt grinder in which the belt travels in a substantially downward direction as the belt contacts the wheel being moved by the elevator. In a further preferred embodiment, the polishing belt grinder, includes a variable pressure system, preferably a hydraulic or air cylinder-piston assembly, in communication with the grinding belt, acting to provide effective contact of the polishing element with the passing wheel so as to polish at least a portion of the wheel.
The present apparatus furthermore includes a Brinell testing system located adjacent to the travel path of the elevator so as to determine the Brinell hardness of that wheel being retained in a substantially vertical position by the receiving means. The Brinell hardness determinations are made on the portion or portions of the surface of the wheel previously polished by the polishing mechanism. Any suitable type of Brinell testing system may be employed in the present apparatus. The conventional "piston-type" Brinell testing system, commonly used to measure the hardness of railway vehicle wheels, is a preferred system.
In another embodiment, the Brinell testing system is located above the polishing element. In this embodiment, the wheel being retained by the receiving means is raised by the elevator past the polishing mechanism and then to the Brinell testing system. Preferably, the wheel comes to a stop, at least momentarily, while the Brinell hardness determinations are being made. After the determination is made, the wheel is lowered away from the Brinell testing system. The wheel is maintained in a substantially vertical position throughout the cycle just described.
In another embodiment, the present apparatus comprises a release mechansim, preferably located near the lower terminous of travel of the elevator. This release mechanism acts to dislodge the wheel from the receiving means after the Brinell determinations have been made. Preferably, the elevator lowers the wheel from the Brinell testing system down to substantially the level at which the wheel was first accepted by the receiving means. At this point, the release mechanism acts to dislodge the already tested wheel from the receiving means. After this wheel has been removed, the receiving means is again ready to accept another wheel for testing. This cycle may be repeated as often as required.
These and other aspects and advantages of the present invention are set forth in the following detailed description and claims, particularly when considered in conjunction with the accompanying drawings in which like parts bear like reference numerals.